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I/o control with vcl – Wesley BC-620-4CA User Manual

Page 91

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Curtis 1234/36/38 Manual,

OS

11

87

2 3 J U LY 2 0 0 8 D R A F T

VCL RUNTIME RATES

VCL is an interpreted language. Each line of VCL code is converted (compiled)
into a set of codes and then flash loaded into the controller. The controller
interprets these codes one line at a time while the system is powered up. Here
are the processing rates of the various functions:

FUNCTION

FUNCTION

FULL

NAME

INSTANCES

SERVICE

RATE

ABS

Absolute Value

2

4 ms

ADC

Analog to Digital Converter Input

2

1 ms

CAN

CAN Communications

15

4 ms

CPY

Copy

8

4 ms

DLY

Delay

32

1 ms

FLT

Filter

4

1 ms

LIM

Limit

4

4 ms

MAP

Map

4

4 ms

MTD

Multiply then Divide

4

4 ms

NVM

Non-Volatile Memory

38

2 ms

PID

Proportional Integral Derivative

2

4 ms

POT

Potentiometer Input

2

8 ms

PWM

Pulse Width Modulated Output

6

4 ms

RMP

Ramp

4

1 ms

SCL

Scaling

4

4 ms

SEL

Selector, 2-position switch

8

4 ms

SEL_4P

Selector, 4-position switch

8

32 ms

SW

Switch Input

1

*

4 ms

TMR

Timers (hourmeters)

3

1 ms

*

There is only one Switch variable; it has 16 associated bit-variables.

I/O CONTROL WITH VCL

Digital Inputs

The 1234 controller has at total of 16 digital inputs, and the 1236/38 has 15.
Eight are switch inputs (Sw_1 through Sw_8) on all the models; the 1234 has
a ninth switch input, Sw_16. These switch inputs are shown on the standard
wiring diagram (Figure 3, page 12). The remaining seven digital inputs are less
obvious: one on each driver and digital output (Sw_9 through Sw_15). These
can be used as digital inputs or to sense the state of the output or its wiring
(e.g., open coil check).

To address a digital input in a VCL program, use the desired input label

(Sw_1 through Sw_16). You must use On or Off in the code when determining
a switch state; using true/false or 1/0 will give erroneous results.

7 — VCL